Annular variable propeller and method of use thereof

Abstract

The application provides a ring-shaped variable propeller and a use method thereof, and belongs to the propeller field. The propeller blade comprises a main body part, a deformation part and a movable part. The deformation part is arranged in a cavity. A window is arranged in the middle of the deformation part. The window is surrounded by two side edges, and the two side edges are located on both sides of the middle line of the propeller blade. When the window is opened, the two side edges are bent into an arc shape. When the window is closed, the two side edges are contracted and straightened along the extension direction and abut against each other. The movable part is arranged in the window and simultaneously contacts the two side edges. The movable part moves along the middle line and simultaneously bends the two side edges from the straightened state into the arc shape. Through the ring-shaped structure of the propeller blade tip, the movement of fluid from the pressure surface of the propeller to the suction surface under the high-speed working condition is inhibited, so that the blade tip vortex is inhibited, the propelling efficiency of the propeller is improved, and the acoustic performance is improved. Meanwhile, the movable part controls the variable skeleton to be bent into an arc shape or straightened, the window in the middle of the propeller blade is opened or closed, and the propeller reaches the best hydrodynamic state under the high-speed and low-speed working conditions.

Description

Technical Field

[0001] This invention relates to the field of propeller technology, and more particularly to a ring-shaped variable propeller and its usage method. Background Technology

[0002] Propellers are an important form of propulsion in the marine industry. Existing propeller designs have become quite mature and are no longer sufficient to meet the ever-increasing hydrodynamic and acoustic performance requirements of next-generation ships and unmanned underwater vehicles. Therefore, it is necessary to develop new propeller configurations.

[0003] During propeller operation, a suction zone is generated on the surface in front of the blade, and a pressure zone is generated on the surface behind it. Under the influence of the pressure difference, the fluid moves along the blade tip from the pressure surface to the suction surface and interacts with the low-pressure fluid on the suction surface to generate vortices, known as blade tip vortices. The periodic shedding of blade tip vortices causes drastic changes in the pressure on the propeller surface, which not only affects propulsion efficiency but also produces cavitation, one of the main sources of flow noise.

[0004] Publication number CN115892412A discloses a design for an annular blade propeller, in which the tips of two blades are connected to form an annular blade structure. This configuration can suppress the movement of fluid from the pressure surface to the suction surface at the blade tip, thereby suppressing the generation of tip vortices and improving the acoustic performance of the propeller. However, the problem with this design is that when the tip vortex is weak at low operating speeds, the hydrodynamic performance of the annular propeller blade is weaker than that of a conventional propeller configuration. Summary of the Invention

[0005] In view of this, the present invention proposes an annular variable propeller and its usage method to solve the problem that the hydrodynamic performance of current annular propeller blades is weaker than that of traditional propeller configurations when the tip vortex is weak at low speeds.

[0006] The technical solution of the present invention is implemented as follows: The present invention provides an annular variable propeller having blades, the blades including a main body, a deformation part, and a movable part; a cavity is opened in the middle of the main body; the deformation part is disposed in the cavity, and a window is disposed in the middle of the deformation part, the window being surrounded by two sides, the two sides being located on both sides of the centerline connecting the root and tip of the blade; when the window is open, the two sides bend into an arc shape and move away from each other in the middle; when the window is closed, the two sides contract and straighten along their extension direction and abut against each other; the movable part is disposed in the window and simultaneously contacts the two sides, the movable part moves along the centerline and causes the two sides to simultaneously bend from a straight state into an arc shape.

[0007] Based on the above technical solution, preferably, the deformable part includes a variable skeleton and a skin; two variable skeletons are arranged in the cavity and symmetrically arranged on both sides of the center line. The two ends of the variable skeletons extend along the center line and are connected to the main body. In the initial state, the two variable skeletons are straightened and abut against each other. The two variable skeletons divide the cavity into two chambers. The two variable skeletons can extend along their extension direction and bend into an arc shape, so that the middle parts of the two variable skeletons are far apart and the area of ​​the two chambers is reduced at the same time, and a window is formed between the two variable skeletons; two skins are respectively arranged in the two chambers and respectively cover the two variable skeletons. The skins elastically extend or contract and tighten with the deformation of the variable skeletons; a movable part is arranged between the two variable skeletons and simultaneously contacts the two variable skeletons. The movable part moves along the center line and simultaneously bends the two variable skeletons into an arc shape, and the middle parts of the two variable skeletons are far apart.

[0008] More preferably, the two variable frames are arranged in an X-shape, with the two variable frames overlapping and abutting at the intersection; when the two variable frames are straightened, the two skins overlap and contact each other tightly, closing the window; when the two variable frames are straightened, the intersection of the two variable frames is close to the tip of the propeller blade.

[0009] More preferably, the distance between the ends of the two variable frames facing the blade tip is greater than the distance between the ends of the two variable frames facing the blade root; when the two variable frames are straightened, the movable part is located between the ends of the two variable frames facing the blade root; when the two variable frames are bent into an arc shape, the movable part is located between the ends of the two variable frames facing the blade tip.

[0010] More preferably, the movable part includes baffles and rollers; two baffles are symmetrically arranged on both sides of the blade surface, and two variable frames are sandwiched between the two baffles; two rollers are arranged between the two baffles, and the rollers are provided with grooves on their surfaces and are movably mounted on the two variable frames through the grooves, and the rollers move along the variable frames.

[0011] More preferably, it also includes a winding mechanism and a cable; two winding mechanisms are symmetrically arranged on both sides of the blade surface and located at the blade tip; the two ends of the cable extend along the centerline, one end of the cable is fixed to the baffle and the other end is wound inside the winding mechanism.

[0012] More preferably, the cross-section of the variable skeleton material includes a carbon nanotube electrothermal layer and a shape memory alloy layer; the variable skeleton is a cylindrical rod; the carbon nanotube electrothermal layer is disposed in the core of the rod of the variable skeleton, and the carbon nanotube electrothermal layer releases heat when energized; the shape memory alloy layer is disposed on the outer layer of the carbon nanotube electrothermal layer, the outer layer of the shape memory alloy layer deforms when heated and extends along its extension direction, and a skin is applied to the outer surface of the shape memory alloy layer.

[0013] More preferably, the material cross-section of the variable skeleton also includes a cooling pipe layer; the cooling pipe layer is disposed on the outer layer of the shape memory alloy layer, a cooling medium flows through the inside of the cooling pipe layer and causes the shape memory alloy layer to be straightened by cold deformation and contraction, and a skin is laid on the outer surface of the cooling pipe layer.

[0014] A further preferred embodiment includes a power supply and a switching switch. The power supply is located inside the propeller and is connected in series with two carbon nanotube heating layers. The power supply powers the carbon nanotube heating layers by energizing them and releasing heat. The switching switch is electrically connected to the power supply and can turn the power supply on or off.

[0015] On the other hand, the present invention also provides a method of using a ring-shaped variable propeller, which includes the following steps: Step 1, in the initial state, the two variable frames are straightened and the skin is elastically extended, the two variable frames abut against each other and the two skins are tightly pressed together to close the window, and the movable part is disposed between the ends of the two variable frames facing the blade root; Step 2, the movable part moves along the centerline to between the ends of the two variable frames facing the blade tip, and the two variable frames are bent into an arc shape to form a window, the middle parts of the two variable frames are far apart, and the two skins are gradually contracted and tightened from the ends of the variable frames to the middle; Step 3, the two variable frames contract along their extension direction and are straightened again, the movable part moves back along the centerline to between the ends of the two variable frames facing the blade root, and the window is closed again.

[0016] The annular variable propeller and its method of use of the present invention have the following advantages over the prior art:

[0017] (1) The present invention suppresses the movement of fluid from the pressure surface to the suction surface of the propeller under high speed conditions by using the annular structure of the propeller blade tip, thereby suppressing the blade tip vortex and improving the propeller's propulsion efficiency and acoustic performance; at the same time, the movable part controls the variable frame to bend into an arc or straighten, so that the window in the middle of the blade opens or closes, so that the propeller can achieve the best hydrodynamic state under both high and low speed conditions.

[0018] (2) The present invention provides two deformable skeletons with overlapping skins, which provides a certain installation space for the movable part and allows the movable part to bend into an arc shape to form a window when it moves.

[0019] (3) The present invention sets the variable skeleton mainly to be made of shape memory alloy material, and heats and cools it through carbon nanotube electrothermal layer and cooling pipeline layer to make the shape memory alloy layer deform. It can control the curvature of the variable skeleton to bend into an arc more quickly and accurately, thereby controlling the size of the window opening and closing area. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a side view of the annular propeller of the present invention, wherein (a) is the annular propeller in a deformed state and (b) is the annular propeller in an initial state.

[0022] Figure 2 This is a front view of the initial state of the blade of the present invention;

[0023] Figure 3 This is a front view of the deformation state of the blade of the present invention;

[0024] Figure 4 This is a perspective view of the internal structure of the blade of the present invention;

[0025] Figure 5 This is a front view of the initial state of the internal structure of the blade of the present invention.

[0026] Figure 6 This is a front view of the deformation state of the internal structure of the blade of the present invention;

[0027] Figure 7 For the present invention Figure 6 Enlarged view of point A in the middle;

[0028] Figure 8 This is a cross-sectional view of the blade root position of the propeller blade of the present invention;

[0029] Figure 9 For the present invention Figure 8 Enlarged view of point B in the middle;

[0030] Figure 10 This is a cross-sectional view of the material of the variable skeleton of the present invention.

[0031] In the diagram: 10. Blade; 1. Main body; 101. Cavity; 102. Chamber; 2. Deformation part; 21. Variable frame; 211. Carbon nanotube electrothermal layer; 212. Shape memory alloy layer; 213. Cooling pipe layer; 22. Skin; 201. Window; 3. Movable part; 31. Baffle; 32. Roller; 4. Winding mechanism; 5. Cable; 6. Power supply; 7. Switch. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, combined with Figure 2 , Figure 3 and Figure 8 The present invention provides an annular variable propeller, comprising a hub and a plurality of blades 10 arranged around the hub.

[0034] At high speeds, compared to traditional fan-bladed propellers, the annular structure of the annular propeller blades can suppress fluid movement from the pressure side to the suction side, thereby suppressing the generation of tip vortices. However, at low speeds, the annular structure of the annular propeller blades can actually increase fluid movement from the pressure side to the suction side, which is detrimental to the propeller achieving optimal hydrodynamic performance. Based on these reasons, the design concept of this invention is to control the deformability of the central structure of the propeller, so that it is in an open state to form an annular propeller blade at high speeds, and in a closed state to form a traditional fan-bladed propeller blade at low speeds.

[0035] The blade 10 includes a main body 1, a deformation part 2, and a movable part 3.

[0036] A cavity 101 is provided in the middle of the main body 1.

[0037] The deformation section 2 is disposed within the cavity 101, and a window 201 is provided in the center of the deformation section 2. The window 201 is formed by two sides located on both sides of the centerline connecting the root and tip of the blade 10. When the window 201 is open, the two sides bend into an arc shape and move away from each other in the middle. When the window 201 is closed, the two sides contract and straighten along their extension direction and abut against each other. Specifically, the extension direction of the sides is their length direction, so the length of the sides changes during the opening and closing of the window 201.

[0038] The movable part 3 is disposed within the window 201 and simultaneously contacts both sides. The movable part 3 moves along the centerline, causing both sides to simultaneously bend from a straight state into an arc shape. The principle of this invention is somewhat similar to a zipper; the two sides can be regarded as zipper pulls, and the movable part 3 as the zipper tab. Since the length of the cavity 101 is fixed, the sides will bend when they extend, but the direction of bending is uncertain. Therefore, by moving the movable part 3, the sides are separated, causing the middle parts of the two sides to move away from each other, so that when the two sides extend, they bend towards the edge of the cavity 101, thereby forming the window 201.

[0039] The purpose of this invention is to eliminate tip vortices generated at the blade tip position of the propeller as much as possible. Therefore, the window 201 in this invention is set near the blade tip of the propeller blade 10, but it can also be set in the middle of the entire propeller blade 10. Although the width of the window 201 in the open state will increase with the increase of propeller speed, when the size of the window 201 increases to a certain range, its effect of reducing tip vortices will also reach its peak, or even decrease. Therefore, the window 201 does not need to be able to open very wide. The purpose of this invention is to provide a technical implementation method so as to solve the problem of opening or closing the window 201 at the blade tip position of the propeller blade 10 according to the operating conditions under high speed and low speed conditions.

[0040] exist Figure 4 In a preferred embodiment shown, the window 201 is surrounded by two sides, and in a specific implementation, the deformable part 2 includes a variable skeleton 21 and a skin 22.

[0041] Two variable skeletons 21 are disposed within the cavity 101 and symmetrically arranged on both sides of the centerline. The ends of each variable skeleton 21 extend along the centerline and connect to the main body 1. Since the extension direction of the ends of the variable skeletons 21 deflects when they are bent into an arc, the ends of the variable skeletons 21 can be fixed to a hinged connector. Initially, the two variable skeletons 21 are straightened and abut against each other, making them parallel and tightly pressed together. Therefore, the two variable skeletons 21 divide the cavity 101 into two equal chambers 102. When the two variable skeletons 21 extend along their extension direction, since the length of the cavity 101 is fixed, the variable skeletons 21 bend and form an arc, thus moving the middle parts of the two variable skeletons apart and simultaneously reducing the area of ​​the two chambers 102, forming a window 201 between the two variable skeletons 21.

[0042] The skin 22 is generally made of a high-strength and high-toughness elastic rubber material, such as methyl vinyl silicone rubber or polyether ester elastic fiber. Two skins 22 are respectively disposed within two cavities 102 and respectively cover two variable skeletons 21. The skin 22 elastically extends or contracts and tightens according to the deformation of the variable skeletons 21. Specifically, the edges of the skin 22 can be fixed to the inner edge of the cavity 101 by clamping, bonding, or riveting. Because it needs to cover the variable skeletons 21, after one end of the skin 22 is fixed, the other end needs to cross over the variable skeletons 21 to cover them before being fixed to the inner edge of the cavity 101.

[0043] The movable part 3 is positioned between the two variable frames 21 and is in contact with both variable frames 21. Since the movable part 3 is positioned between the two variable frames 21, when the movable part 3 moves along the center line, it will push the two variable frames 21 apart to both sides, so that when the two variable frames 21 are bent into an arc, their middle parts will move away from each other, thus forming a window 201.

[0044] exist Figure 5 In a preferred embodiment shown, since the movable part 3 needs to be set between the two variable skeletons 21, there will be a large gap between the two variable skeletons 21, making it impossible to close the window 201. Therefore, in this embodiment, the two variable skeletons 21 are designed to be arranged in an X-shape, and the two variable skeletons 21 overlap and abut at the intersection. When the two variable skeletons 21 are straightened, the two skins 22 overlap and contact and close the window 201, so that there will be a triangular gap in the part of the two variable skeletons 21 below the intersection. This gap is large enough to accommodate the movable part 3. As long as this gap is small, it can be regarded as the window 201 being in a closed state. When the two variable skeletons 21 are straightened, the intersection of the two variable skeletons 21 is close to the tip of the blade 10. Since the variable skeletons 21 have already bent due to the extension of their length, when the two variable skeletons 21 cross, the variable skeletons 21 will bend towards the inner edge of the cavity 101 instead of bending towards the center of the cavity 101. This ensures that the bending direction of the two variable skeletons 21 can form the window 201.

[0045] exist Figure 6 In a preferred embodiment shown, to ensure that the triangular gap between the two variable frames 21 below the intersection is sufficiently small, the distance between the ends of the two variable frames 21 facing the tip of the blade 10 is greater than the distance between the ends of the two variable frames 21 facing the root of the blade 10. Therefore, when the two variable frames 21 are straightened, the movable part 3 is located between the ends of the two variable frames 21 facing the root of the blade 10. At this time, the intersection of the two variable frames 21 is also close to the root of the blade 10, and the triangular gap is very small, which basically does not affect the sealing effect of the window 201. When the two variable frames 21 are bent into an arc shape, the movable part 3 is located between the ends of the two variable frames 21 facing the tip of the blade 10. At this time, the intersection of the two variable frames 21 is also close to the tip of the blade 10.

[0046] exist Figure 7 In a preferred embodiment shown, combined with Figure 9 The movable part 3 needs to function similarly to a zipper pull, so the movable part 3 needs to be able to move along the variable frame 21, and the movable part 3 also needs to be unable to detach from the two variable frames 21. Specifically, the movable part 3 includes a baffle 31 and a roller 32.

[0047] Two baffles 31 are symmetrically arranged on both sides of the blade 10, and two variable frames 21 are sandwiched between the two baffles 31. The outer surface of the baffles 31 can be designed as a contoured arc surface to reduce the adverse effect on the streamline shape of the propeller. The inner edge of the baffle 31 is preferably in close contact with the skin 22 to avoid gaps between the baffles 31 and the skin that would affect the propeller's performance.

[0048] Two rollers 32 are disposed between two baffles 31. The rollers 32 have grooves on their surfaces and are movably mounted on the two variable frames 21 through these grooves. The rollers 32 move along the variable frames 21. Since the movable part 3 moves closely following the intersection of the two variable frames 21, and the width of the intersection of the two variable frames 21 remains essentially constant, the movable part 3 can be confined between the two variable frames 21 by the two rollers 32 without disengaging.

[0049] exist Figure 2 In a preferred embodiment shown, in order for the movable part 3 to move closely following the intersection of the two variable frames 21, a winding mechanism 4 and a cable 5 are also included.

[0050] Two winding mechanisms 4 are symmetrically arranged on both sides of the blade 10 and located at the tip of the blade 10. The winding mechanism 4 is embedded in the main body 1, and a protrusion can be provided on the main body 1 to allow the free end of the winding mechanism 4 to extend out.

[0051] The cable 5 extends along the centerline at both ends, with one end fixed to the baffle 31 and the other end wound inside the winding mechanism 4. The cable 5 is preferably made of high-strength carbon fiber.

[0052] It should be noted that since the propeller opens window 201 at high speeds, the exposed length of cable 5 is very short in this situation, which avoids adverse effects on the propeller. When the propeller is at low speeds, even if the cable 5 extends a longer length, it will not have a significant adverse effect on the propeller due to the low propeller speed and the thinness of cable 5. This also avoids the problem that the centrifugal force at high speeds may break cable 5.

[0053] exist Figure 10 In a preferred embodiment shown, in order to enable the variable skeleton 21 to elastically extend when heated, the material cross-section of the variable skeleton 21 includes a carbon nanotube electrothermal layer 211 and a shape memory alloy layer 212.

[0054] The variable skeleton 21 is a cylindrical rod, which facilitates bending deformation and straightening. Since the extension direction of the end of the variable skeleton 21 will deflect when it is bent into an arc, the end of the variable skeleton 21 is fixed to a hinge connector. The variable skeleton 21 and the hinge connector can be integrally formed and can be manufactured by additive manufacturing technology.

[0055] A carbon nanotube electrothermal layer 211 is disposed in the core of the rod of the variable skeleton 21, and the carbon nanotube electrothermal layer 211 releases heat when energized.

[0056] A shape memory alloy layer 212 is disposed outside the carbon nanotube electrothermal layer 211. The outer layer of the shape memory alloy layer 212 deforms upon heating and extends along its extension direction. A skin 22 is applied to the outer surface of the shape memory alloy layer 212 to prevent damage to the skin 22 due to the exothermic effect of the carbon nanotube electrothermal layer 211 when it comes into contact with the skin 22. It should be noted that modern research has found that some metallic materials, after undergoing significant plastic deformation, will extend back to their original shape upon heating, and then shrink upon cooling. The same material, within a certain temperature range, can exhibit strains up to 10% and still return to its original shape upon unloading. These unusual effects are respectively called thermo-shape memory and superelasticity (elastic shape memory). Both effects depend on the occurrence of a specific type of phase transformation, called thermoelastic martensitic transformation. The shape memory alloy layer 212 in this case is made of such a metal, generally a nickel-titanium based alloy, such as titanium-nickel alloy, titanium-nickel-niobium alloy, titanium-nickel-palladium alloy, etc., but copper-based alloys or iron-based alloys can also be used. Specifically, the shape memory alloy layer 212 is composed of nickel, titanium and copper, with the mass percentages of nickel, titanium and copper being 48.0-51.0% Ni, 43.5-47.5% Ti and 4.5-5.5% Cu.

[0057] exist Figure 10 In a preferred embodiment shown, in order to enable the variable skeleton 21 to undergo elastic contraction and straightening upon cooling, the material cross-section of the variable skeleton 21 further includes a cooling pipe layer 213.

[0058] The cooling pipe layer 213 is disposed on the outer layer of the shape memory alloy layer 212. A cooling medium flows through the cooling pipe layer 213, causing the shape memory alloy layer 212 to straighten due to cold deformation and contraction. A skin 22 is applied to the outer surface of the cooling pipe layer 213. The shape memory alloy layer 212, the cooling pipe layer 213, and the carbon nanotube electrothermal layer 211 can all be integrally formed using additive manufacturing technology.

[0059] In addition, since the propeller of the present invention is typically used in water or underwater vehicles, the cooling medium of the cooling pipe layer 213 can be directly taken from the ambient water.

[0060] exist Figure 10In a preferred embodiment shown, in order to control the heating temperature and heating time of the carbon nanotube heating layer 211, a power supply 6 and a switching switch 7 are also included.

[0061] The power supply 6 is located inside the propeller and is connected in series with two carbon nanotube heating layers 211. The power supply 6 powers the carbon nanotube heating layers 211 to release heat. The power supply 6 can be DC or AC.

[0062] The switch 7 is electrically connected to the power supply 6, and the switch 7 can disconnect or connect the power supply 6.

[0063] like Figure 1 As shown, combined with Figure 2 , Figure 3 , Figure 5 and Figure 6 The present invention discloses a method for using a ring-shaped variable propeller, employing any of the ring-shaped variable propellers described above, comprising the following steps.

[0064] Step 1: In the initial state, the two variable frames 21 are straightened and the skin 22 is elastically extended. The two variable frames 21 abut against each other and the two skins 22 are pressed tightly against each other to close the window 201. The movable part 3 is located between the ends of the two variable frames 21 facing the root of the blade 10.

[0065] Specifically, since the two variable frames 21 are arranged in a cross manner, when the two variable frames 21 are straightened, there will be a small triangular gap between the ends of the two variable frames 21 near the root of the blade 10. This gap is sufficient to accommodate the movable part 3. At this time, the two rollers 32 of the movable part 3 are respectively engaged with the two rod-shaped variable frames 21 through the wheel groove.

[0066] Step 2: The movable part 3 moves along the centerline to the ends of the two variable frames 21 facing the tips of the blades 10, and the two variable frames 21 are bent into an arc shape to form a window 201. The middle parts of the two variable frames 21 are far apart from each other, and the two skins 22 are gradually contracted and tightened from the ends of the variable frames 21 to the middle.

[0067] Specifically, power supply 6 is turned on to supply power to carbon nanotube electrothermal layer 211 and cause it to release heat. The heat is conducted into shape memory alloy layer 212, causing variable skeleton 21 to extend in its extension direction. However, the bending deformation direction of variable skeleton 21 is uncertain at this time. Therefore, winding mechanism 4 is activated to pull movable part 3 towards blade tip of blade 10 via cable 5. The forward movement of movable part 3 will cause two rollers 32 to gradually push the two variable skeletons 21 to bend and deform outward. During this process, the intersection of the two variable skeletons 21 also gradually moves forward. At the same time, since movable part 3 always moves close to the intersection of the two variable skeletons 21, the two rollers 32 of movable part 3 will not detach from the two variable skeletons 21. When movable part 3 finally moves to blade tip of blade 10, the two variable skeletons 21 also form window 201.

[0068] Step 3: The two variable frames 21 retract along their extension direction and straighten again, the movable part 3 moves along the centerline to the ends of the two variable frames 21 facing the blade root of the blade 10, and closes the window 201 again.

[0069] Specifically, turning off the power supply 6 stops the heating and introduces the cooling medium into the cooling pipe layer 213, causing the variable frame 21 to contract and straighten in its extension direction. At this time, the winding mechanism 4 can be released, so that the movable part 3 loses the tension restraint of the cable 5. As the two variable frames 21 are straightened, their intersection also gradually moves backward, which will push the movable part 3 to gradually move backward and reset.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ring-shaped variable propeller having blades (10), characterized in that: The blade (10) includes a main body (1), a deformation part (2), and a movable part (3); A cavity (101) is provided in the middle of the main body (1); The deformation part (2) is disposed in the cavity (101). A window (201) is provided in the middle of the deformation part (2). The window (201) is surrounded by two sides, which are located on both sides of the centerline connecting the root and tip of the blade (10). When the window (201) is open, the two sides are curved into an arc and their middle parts are far apart. When the window (201) is closed, the two sides contract and straighten along their extension direction and abut against each other. The movable part (3) is located inside the window (201) and simultaneously contacts the two sides. The movable part (3) moves along the centerline and simultaneously bends the two sides from a straight state into an arc shape.

2. The annular variable propeller according to claim 1, characterized in that: The deformable part (2) includes a variable skeleton (21) and a skin (22); Two variable skeletons (21) are arranged in the cavity (101) and symmetrically arranged on both sides of the center line. The two ends of the variable skeletons (21) extend along the center line and are connected to the main body (1). In the initial state, the two variable skeletons (21) are straightened and abut against each other. The two variable skeletons (21) divide the cavity (101) into two cavities (102). The two variable skeletons (21) can extend along their extension direction and bend into an arc shape, so that the middle parts of the two variable skeletons (21) are far apart from each other and the area of ​​the two cavities (102) is reduced at the same time, and a window (201) is formed between the two variable skeletons (21). The two skins (22) are respectively disposed in the two cavities (102) and respectively cover the two variable skeletons (21). The skins (22) elastically extend or contract and tighten as the variable skeletons (21) deform. The movable part (3) is disposed between the two variable skeletons (21) and simultaneously contacts the two variable skeletons (21). The movable part (3) moves along the center line and simultaneously bends the two variable skeletons (21) into an arc shape, and moves the middle parts of the two variable skeletons (21) away from each other.

3. The annular variable propeller according to claim 2, characterized in that: The two variable skeletons (21) are arranged in an X-shape and overlap and abut at the intersection. When the two variable skeletons (21) are straightened, the two skins (22) overlap and come into close contact with each other, thus closing the window (201); When the two variable frames (21) are straightened, the intersection of the two variable frames (21) approaches the tip of the blade (10).

4. The annular variable propeller according to claim 3, characterized in that: The distance between the ends of the two variable skeletons (21) facing the tip of the blade (10) is greater than the distance between the ends of the two variable skeletons (21) facing the root of the blade (10). When the two variable frames (21) are straightened, the movable part (3) is located between the ends of the two variable frames (21) facing the root of the blade (10); When the two variable frames (21) are bent into an arc shape, the movable part (3) is located between the ends of the two variable frames (21) facing the tip of the blade (10).

5. A ring-shaped variable propeller according to claim 2, characterized in that: The movable part (3) includes a baffle (31) and a roller (32); Two baffles (31) are symmetrically arranged on both sides of the blade (10) plate surface, and two variable frames (21) are sandwiched between the two baffles (31); Two rollers (32) are disposed between two baffles (31). The rollers (32) have grooves on their surfaces and are movably disposed on two variable frames (21) through the grooves. The rollers (32) move along the variable frames (21).

6. A ring-shaped variable propeller according to claim 5, characterized in that: It also includes a winding mechanism (4) and a cable (5); The two winding mechanisms (4) are symmetrically arranged on both sides of the blade (10) and located at the tip of the blade (10); The cable (5) extends along the centerline at both ends, with one end fixed to the baffle (31) and the other end wound in the winding mechanism (4).

7. A ring-shaped variable propeller according to claim 2, characterized in that: The material cross-section of the variable skeleton (21) includes a carbon nanotube electrothermal layer (211) and a shape memory alloy layer (212); The variable skeleton (21) is a cylindrical rod; The carbon nanotube electrothermal layer (211) is disposed in the core of the rod body of the variable skeleton (21), and the carbon nanotube electrothermal layer (211) releases heat when energized; The shape memory alloy layer (212) is disposed on the outer layer of the carbon nanotube electrothermal layer (211). The outer layer of the shape memory alloy layer (212) is deformed by heat and extends along its extension direction. A skin (22) is applied to the outer surface of the shape memory alloy layer (212).

8. A ring-shaped variable propeller according to claim 7, characterized in that: The material cross-section of the variable skeleton (21) also includes a cooling pipe layer (213); The cooling pipe layer (213) is disposed on the outer layer of the shape memory alloy layer (212). The cooling medium flows through the interior of the cooling pipe layer (213) and causes the shape memory alloy layer (212) to be straightened by cold deformation and contraction. The outer surface of the cooling pipe layer (213) is covered with a skin (22).

9. A ring-shaped variable propeller according to claim 8, characterized in that: It also includes a power supply (6) and a switch (7), The power source (6) is located inside the propeller. The power source (6) is connected in series with two carbon nanotube electrothermal layers (211). The power source (6) supplies power to the carbon nanotube electrothermal layers (211) by energizing and releasing heat. The switching switch (7) is electrically connected to the power supply (6), and the switching switch (7) cuts off or connects the power supply (6).

10. A method of using a ring-shaped variable propeller, employing the ring-shaped variable propeller as described in any one of claims 2 to 9, characterized in that: Includes the following steps, Step 1, in the initial state, the two variable skeletons (21) are straightened and the skin (22) is elastically extended. The two variable skeletons (21) abut against each other and the two skins (22) are pressed tightly against each other to close the window (201). The movable part (3) is set between the ends of the two variable skeletons (21) facing the blade root of the blade (10). Step 2, the movable part (3) moves along the centerline to between the ends of the two variable skeletons (21) facing the blade tip (10), and the two variable skeletons (21) are bent into an arc shape and form a window (201). The middle parts of the two variable skeletons (21) are far apart from each other, and the two skins (22) are gradually contracted and tightened from the ends of the variable skeletons (21) to the middle. Step 3: The two variable skeletons (21) retract and straighten again along their extension direction, and the movable part (3) moves back along the centerline to the ends of the two variable skeletons (21) facing the blade root of the blade (10), and closes the window (201) again.

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